HST is in a 96-minute orbit, up to half of which is blocked by the Earth, depending on where in the sky you point it. Getting time on it is an extremely competi

HST is in a 96-minute orbit, up to half of which is blocked by the Earth, depending on where in the sky you point it. Getting time on it is an extremely competitive process - the recent cycle had over a thousand proposals, requesting over 24,000 orbits worth of observing time, and they had only 2700 orbits to allocate [1]. This sort of proposal pressure (over 9:1 oversubscription) leads to very conservative proposals, where we request absolute minimums and emphasize that even a non-detection will lead to publishable science in such and such a way. Getting over 60 orbits to point at a blank field would have been frankly impossible through the regular time allocation process, not because the science wasn't excellent, not because it wouldn't be recognized as excellent, but because it would crowd out other science that could be done with far fewer orbits per project. The telescope administrators explicitly recognized this problem when they set up the Director's Discretionary Time process (and this is common to all telescopes now) - sometimes you need someone with the authority to just roll the dice on a long shot. [1] https://www.stsci.edu/contents/newsletters/2019-volume-36-issue-02/hst-cycle-27-proposal-selection https://www.stsci.edu/contents/newsletters/2019-volume-36-is...